Furnace.



, Patented July I, I902. P. CORRIGAN.

F U B N A C E (Application filed Mar. 30, 1901.) 4

(No Model.)

WITNESSES UNITED STATES TENT OFFICE.

PHILIP CORRIGAN, OF W'AKEFIELD, NET/V YORK.

FURNACE.

SPECIFICATION refinin part of Letters Patent No. 703,768, dated July 1,1902.

Ap IiOationJfiIedMarch 30, 1901. Serial No. 53,722. (No model.)

T0 aZZ whom/it may concern: 7

Be it known that LPHI IP CORRIGAN, a citizen of the United States,residing in Wakefield, in the borough of the Bronx, in the city andState of'N ewrYork, have invented'a certain new and useful Improvementin Metallurgical Furnaces,of which the following is a specification.

I have in my experiments applied the improvement to furnaces of moderatesize burning gas as a fuel andused'for melting and refiningprecious'metals and will-describe it as thus applied. It presents thepipes conspicuously in sight under all conditions,*allowing constantinspection and easy acoess*for adjustment or repairs when necessary, andespecially provides for the easy removal and exchange of the burnersthrough which the mixture of .air and gas is projected into the furnace.I

I designate as burners the pipes usually arranged tangentially in thewalls of the furnace. They correspond generally to the parts sometimesdesignated twyersin large furnaces for reducing and melting metals, the

inner end of each coinciding approximately with the inner face of thefurnace, the main body lying within the wall and the outer end beingadapted for joining to a pipe which supplies air and gas.

My burners may be in whole or in part'of fire-brick, plumbag'omr otherrefractory material; but the outer portion of each, being sufficientlydistant from the heated locality, may be ordinary cast-iron.

My invention allows for so easy exchange that I have in my experimentsmade each entire burner a single casting of ordinary soft iron.

The following is a description of whatjI consider the the best means ofcarrying out the invention.

The accompanying drawings form a part of this specification.

Figure 1 is a side elevation. Fig. 2 is a horizontal section on the line2 2 in Fig. l with portions shown in plan. The remaining figures showportions on a larger scale. Fig. 3 is a plan view, partly in horizontalsection, showing one of my burners and its connection to the otherpipes. Fig. 3 is an end view of the outer end, showing the mark by whichthe position of the delivery-slot of the burner is clearly visible fromthe outside. across-section on the line 4 4 in Fig. 3. Fig. 5 is an endview of the delivery-nozzle of the burner. 'Fig. 6 is a horizontalsection of the delivery end and the adjacent portion of the furnaceon'the same scale asin Fig. 3,showing a modificatioma beveled end to theburner; and Fig: 6 shows the preferred plan for marking the outer endwhen such nozzle is used.

Similar letters of reference indicate corresponding parts in all thefigures where they appear.

A is the base or bottom, A the fire-brick lining, andA the exteriorbrick or backing. These latter may usually be of ordinary brick; but theWhole may, if desired, be fire-brick in' as many or fewpieces as may bepreferred.

0 is a rectangular outercasin'g of cast-iron or other suitable materialholding the Whole reliably together. Two smooth tangential passages doare provided on opposite sides of the'furnace,'and in'these my'burnersare inserted by being'Ithrust in ward from the out 'D' D. designatetheinner end sof my burners, each partially closed, but having a liberalslot at extendingdiametrically across.

'Ddesignates the main bodies tapered, as shown.

D is a short screw-threaded portion matching the screw-threads ineither't" 01-5 and D? a cylindrical open-workextension;

D is the closed outer porti'on, carrying a smaller continuation havingits end D squared. A cross-mark d is cut'on' the outer face of theextreme end, which'mark lies in the same plane as the slot cl at theinner end, so that'the mark serves as anindex to show how the'slot isturned. ThG'b'illIl'GIl should always be adjusted with the slotdextending up and down, so that a flame having more height thanthickness'shall result from the combustion of the gas as it flows fromeach slot into the furnace and spirals around therein. The inner ends ofthe burners presented to the interior of the furnace are the parts whichare liable to be destroyed by the heat.

The tapering bodies D of the burners are allowed to fit' easily and maybe left a little Fig. 4 is' loose, or the slight space around each maybe.terial.

packed with fire-clay or other refractory ma- I preferto leave the jointopen.

13 is the pipe, bringing air under pressure which has been forced by ablower, (not shown,') and O is a stop-cock controlling; the How. B is atapering nozzle, through which it is ejected with force into a pipe Bwhere it mingles with combustible gas received under a gentle pressurethrough a pipe E, controlled by a cock F, by the aid of a pump orblower. (Not shown.) The pipe B extends across the front and thencerearward. At points therein on opposite sides of the furnace are twochambers I I, slightly larger than the pipe, each of which serves theimportant function of receiving a burner D, extending through ittransversely and allowing such burner to be easily inserted, adjusted,and

removed. Each chamber I has .a screwthreaded hole 1; in its outer sideand a similar hole i in its inner side. Each chamber I and its holes 6 imust be setin line with one of the tangentially-arranged holes a in thebrick-work, which receive the inner end and main body of each burner.

Three or a larger number of similar burners D must be provided, so as toserve interchangeably. One is introduced in each chamber'I, turning eachproperly to traverse the outer screw-threaded hole i, and again afterafurther thrust to properly enter and engage in the inner hole 2' Afterit is home a detachable stuffing-box M, screw-threaded on its exterior,is slipped over the contracted end D D and engaged in the hole t" andscrewed in. A ring'of any convenient soft packing H is applied initsscrew-threaded interior m, and a ring or gland G, screwthreaded on itsexterior, is applied and turned to properly compress it. I have usedasbestos as packing; but as there is little heat any packing whichwil'lmake a fairly gas-tight joint will serve. The inner end D of the burnershould be about flush with the interior of the furnace. If it extendstoo much it is less able to Withstand the heat, and it should not be toomuch drawn back. Unscrewing the stuffing-box M liberates the burner, sothat the latter can be turned as many half-turns as required in eitherdirection to adjust it farther in or out, taking care to always leave itwith the mark d extending up and down, and alwaysretightening thestuffingbox after such adjustment. The part M serves a doublefunction-one as a stuffing-box and another as a jam-nut, which beingscrewed in with force insures the absolute fixity of the burner until itis again unscrewed. v

The complete removal of the burner and the supplying of another may beeffected in a very short time even when the furnace is at full heat. Toefiect this, I shut the cooks O and F, thus stopping the supply of airand gas, apply a wrench to the outer end of the jam-nut stuffing-box M,(flat places being formed there to allow this without injuringthethreads.) and remove that part. Then apply a proper wrench to thesquared end D and turn the burner, drawing it gradually back. When thescrew-threaded portion D is clear of the screw-threads in the innerorifice '6 the burner may be moved directly outward until thescrew-threads on D contact with the screw-threads in the outer orificei,

when the burner must be again turned until these threads are passed.Then it may be drawn out directly and its hot inner end examined. Ifexchange is expedient, a spare burner is introduced in its place, and areversal of themovements and a proper adj ustment' of the new burner andof thesame stuifing-box jam-nut M, its packing. H, and ring G, or of anew one of each, makes all ready, and the gas and air. being againturned on the furnace is again serving as before.

It is not essential that the air which is allowed to mix with the gas atthe reduced nozzle 13 shall be sufficient to attain complete combustion.The force with which the mixture of air and gas is projected into thefurnace draws in additional air through the small space around mytapering burner, and the air thus received at ordinary pressure inaddition to that received at the earlier stage at a pressure aboveatmosphere together should be a'little more than sufficient to effectcomplete combustion.

The hole a being tapered and the burner D, which fits loosely therein,being also tapered, it follows that the adjustment of the pipe D inwardand outward by the means described will have the effect to modify thequantity of air which isdrawn in at atmospheric pressure around theburner, screwing the burner D in contracting the annular space andreducing the quantity of air admitted through it, and

drawing out the burner D, enlarging such space, and increasing thequantity of air thus admitted.

The general form of my furnace may correspond to one which has beenlongapproved, having sliding doors K, arranged to be moved laterally onsuitable ways to cover and uncover the furnace conveniently whendesired; The flame from my burners travels spirally around in theinterior of the furnace in the approximately annular space between thecrucible W and the inner wall A of the furnace and escapes through theflue a into the chimney. (Not shown.)

My furnace is accessible for inspection or repairs in the ordinarymanner. The provisions for controlling the air and gas may be adjustedwith great nicety and changed without difficulty, as conditions mayrequire,

whilethe furnace is working.

The most likely points to fail in afurnace of this general character arethe inner ends of the burners. My burner may be simply and cheaplyconstructed as asingle casting, the only parts requiring to be finishedbeing the screw-threads on D and the stuffing-box.

IIO

A single stuffing-box may serve with a number of successive burners.

Modifications may be made without departing from the principle orsacrificing the advantages of the invention. lhe form of the casing O,constituting the exterior of the furnace, may be cylindrical or ofvarious other forms instead of rectangular. In such case or in any casethe pipe 13 may be curved instead of having straight portions, as shown.There may be three or four or only one instead of the two burners shown,providing a corresponding number of the other parts.

The inner end of the burner may, if pre ferred, be beveled, as shown inFig. 6. This will allow it to coincide more perfectly with the innersurface of the fire-brick lining A of the furnace; but it interfereswith the nicety of adjustment, forbidding its being left half revolved.When such form is adopted, a mark not extending across, but on one sidealone, as the prick-punch mark 01 may be employed, by which to insurethat it is correctly arranged.

It is not essential that the portion D of the burner becylindricahwithjbars extending longitudinally and all the spaces betweenopen, as shown. It is only essential that it be not too large to allowthe burner to be introduced and withdrawn by longitudinal movements andthat it have liberal apertures-whatis commonly termed open-worktherebeing metal connecting the outer and inner portions of the burner, butwith sufficient spaces to allow the mixture of gas and air to freelytraverse inward from the chamber I, and thence flow without obstructionto the nozzle and be discharged into the furnace.

I claim as my invention 1. In a metallurgical apparatus, a furnace Ahaving a tangential passage a leading from the outside of thefurnace-wall to the interior space of the furnace and a supply-pipe Bing the threads D the portion ,D of the burner being open-work so as toconstitute a strong extension of the burner across the chamber I, but soliberally apertured as to freely admit the gas and air, such apparatusbeing adapted toallow the burner to be ad- 3' usted outward and inwardand to be removed and replaced when required without disturbing theother parts, all substantially as herein specified.

In a metallurgical apparatus having a furnace-lining A with a passage orleading from the outside to the inside of the furnacewall, and asupply-pipe B arranged to bring gases under pressure, a chamber I insaid supply-pipe having the internally-screw-threaded part 1" and alsohaving the internally-screwthreaded part i for holding the burner and aburner D extending longitudinally ofsuch passage and having thescrew-threaded part D thereon, in combination with each other and withthe screw threaded ring M m matched in the screw-threaded orifice t" onthe outer side of said chamber, adapted to serve the double function ofa stuffing-box and a jam-nut, all substantially as herein specified.

In testimony that I claim the invention above set forth I'affix mysignature in presence of two witnesses.

PHILIP CORRIGAN.

Witnesses:

J. B. CLAU'IIOE, M. F. BOYLE.

